shazbot
Posts: 11
Joined: Sat Jun 13, 2015 10:09 am

About the sensors

Wed Dec 21, 2016 4:06 pm

Hi! I stumbled upon this little piece of hardware and found it to be a perfect fun match (perhaps a bit too pricy but whatever) for my project which would be to measure temperature and humidity in our summer house (it would be powered on for 'unlimited' time).

However after reading about it (on this forum and else where) there seems to be some issues about getting the right data (temperature and humidity) from the sensors due to them picking up the heat from the cpu on the pi (it would be pi 3 in my case). This "flaw" sounds to me like it kinda defeats the whole purpose of the board (or some functionally at least).

Have I missed something or is there a workaround for this? I was pretty close to buying it but now it sadly seems like it would be a waste of money (for my project that is).

ElEscalador
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Location: Detroit, MI USA
Contact: Website

Re: About the sensors

Wed Dec 21, 2016 4:46 pm

Move the sensors away from the pi? It's just a few wires - you can extend them.
My Autonomous Robot Project and a few of my other projects below.

https://lloydbrombach.wordpress.com/

alphanumeric
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Location: Sydney, Nova Scotia, Canada

Re: About the sensors

Thu Dec 22, 2016 1:35 pm

I soldered one of these, https://www.adafruit.com/products/1979 to this, https://www.adafruit.com/products/2310 instead of the header that comes with it. I then mounted it between my Pi A+ and my Sense Hat. My temps etc now read correctly. Mine is running 24/7 showing a scrolling Date, Time, Temp, Humidity, Pressure message. I have a Real Time Clock breakout board wired to the Proto Hat so my Pi can keep perfect time without network access. Pictures here if you want to have a look.
https://1drv.ms/f/s!AjOYwiwlwDtpgq8_0VrdS3_H5xL_AA At the moment its not in a case and has no WIFI dongle connected. It runs totally headless. I can adjust the screen brightness and shut it down with the joystick/switch.

shazbot
Posts: 11
Joined: Sat Jun 13, 2015 10:09 am

Re: About the sensors

Thu Dec 22, 2016 3:48 pm

alphanumeric wrote:I soldered one of these, https://www.adafruit.com/products/1979 to this, https://www.adafruit.com/products/2310 instead of the header that comes with it. I then mounted it between my Pi A+ and my Sense Hat. My temps etc now read correctly. Mine is running 24/7 showing a scrolling Date, Time, Temp, Humidity, Pressure message. I have a Real Time Clock breakout board wired to the Proto Hat so my Pi can keep perfect time without network access. Pictures here if you want to have a look.
https://1drv.ms/f/s!AjOYwiwlwDtpgq8_0VrdS3_H5xL_AA At the moment its not in a case and has no WIFI dongle connected. It runs totally headless. I can adjust the screen brightness and shut it down with the joystick/switch.
Oh, this is great. Thank you! And thank you for the pictures.

Probably a dumb question, but in your setup - are you using included header that comes with the stacking between the proto hat and sense the hat?

alphanumeric
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Location: Sydney, Nova Scotia, Canada

Re: About the sensors

Thu Dec 22, 2016 8:18 pm

No I didn't use the header that came with the Proto Hat. If you use that header you can't stack anything on top of the Proto Hat. I used the stacking header in its place. Make sure you get the Proto hat "without" the EPROM.

shazbot
Posts: 11
Joined: Sat Jun 13, 2015 10:09 am

Re: About the sensors

Tue Dec 27, 2016 9:24 am

alphanumeric wrote:No I didn't use the header that came with the Proto Hat. If you use that header you can't stack anything on top of the Proto Hat. I used the stacking header in its place. Make sure you get the Proto hat "without" the EPROM.
Alright, thank you! :)

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bensimmo
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Re: About the sensors

Tue Dec 27, 2016 9:31 am

Remember you can have a play with it and a bit of programming using the emulator in Raspian.
Or in Minecraft
Or on trinket.io

Or if you've not got a Pi then on the new Raspian PC DVD or Pendrive install to practice before you buy.

To be honest there are cheaper ways than the sense hat for just temperature and pressure, but they're not as easy.

A PiZero may be a better option than the Pi3 as well. It doesn't use as much power and gets nowhere near as hot.

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bensimmo
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Location: East Yorkshire

Re: About the sensors

Tue Dec 27, 2016 9:39 am

There is of course nothing to stop you housing the SenseHat away from the Pi, say place the Pi near the PSU and run wires to the SenseHat that can be placed in an 'open' box.
Either all wires to keep it easy via a standard 40pin flat cable or just the wires needed to keep it a bit tidier.

shazbot
Posts: 11
Joined: Sat Jun 13, 2015 10:09 am

Re: About the sensors

Tue Dec 27, 2016 10:10 am

bensimmo wrote:Remember you can have a play with it and a bit of programming using the emulator in Raspian.
Or in Minecraft
Or on trinket.io

Or if you've not got a Pi then on the new Raspian PC DVD or Pendrive install to practice before you buy.

To be honest there are cheaper ways than the sense hat for just temperature and pressure, but they're not as easy.

A PiZero may be a better option than the Pi3 as well. It doesn't use as much power and gets nowhere near as hot.
Oh, I'm looking into buying a PiZero as well, but they are impossible to get a hold of here in sweden.

alphanumeric
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Location: Sydney, Nova Scotia, Canada

Re: About the sensors

Tue Dec 27, 2016 10:51 am

Depending on the case and the Pi you buy, as the Zero comes without the header soldered in. With that Pi you could use a right angled header that would point it straight out the back at a right angle to the sense hat.

If you go with the ribbon cable make sure you use one that is 40 pins 40 wires, not 40 pins 80 wires. An IDE cable will work as long as its the old type not the new type. Or something like this, https://www.adafruit.com/products/1988

If you go with the ribbon cable, make sure you get PIN 1 correct on both ends. I had a friend break his sense hat by mixing one end up. It does not work anymore.

shazbot
Posts: 11
Joined: Sat Jun 13, 2015 10:09 am

Re: About the sensors

Thu Jan 05, 2017 11:50 am

Solder it last night, was so much fun! :D

Compared the readings to our kitchen temperature sensor and it was off by one degrees. Will do some more testing. Thanks for the inspiration!

alphanumeric
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Location: Sydney, Nova Scotia, Canada

Re: About the sensors

Thu Jan 05, 2017 1:06 pm

So which way did you go? Pi Zero, ribbon cable?

shazbot
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Joined: Sat Jun 13, 2015 10:09 am

Re: About the sensors

Sat Jan 14, 2017 8:47 pm

alphanumeric wrote:So which way did you go? Pi Zero, ribbon cable?
Went with the A+ variant :) But will go for the pi zero! So many projects, so little time :lol:

Thanks for the inspiration!

alphanumeric
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Location: Sydney, Nova Scotia, Canada

Re: About the sensors

Sat Jan 14, 2017 9:00 pm

Thanks for the reply, have fun :)

KanoMaster22
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Re: About the sensors

Mon Jan 30, 2017 4:12 pm

perhaps a bit too pricy but whatever
It used to cost £17 everywhere (or about that) and now it costs £30!!!

alphanumeric
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Joined: Tue Jan 19, 2016 2:17 pm
Location: Sydney, Nova Scotia, Canada

Re: About the sensors

Mon Jan 30, 2017 4:26 pm

£25 at Pimoroni, I just ordered another one to play with. =)

alphanumeric
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Joined: Tue Jan 19, 2016 2:17 pm
Location: Sydney, Nova Scotia, Canada

Re: About the sensors

Mon Jan 30, 2017 4:36 pm

If all you want it temp there are options like this, https://www.adafruit.com/products/1603 or https://www.adafruit.com/products/2652 etc

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